New HD missing gigs

Discussion in 'MacBook' started by smmsanders, Oct 23, 2009.

  1. smmsanders macrumors newbie

    Aug 27, 2009
    I recently replaced 60 GB HD on an iBook G4 14", PPC 1.33. I bought a 320 GB Western Digital HD. Before installing the HD, I formatted it with Disk Utility. For some reason, disk utility could only recognize 300 GB. I'm not sure why. Could it be the external hard drive bay that I used? I've installed the HD, and I'm wondering if I can get the extra 20 GB out of my new HD.
  2. old-wiz macrumors G3

    Mar 26, 2008
    West Suburban Boston Ma
    sigh... we get one of these pretty regularly. It all has to do with how they count GB. I have a "320" gb disk in my iMac and HD info reports 297 GB capacity. Plenty of discussion about how they do the counting can be found via an mroogle search.
  3. Loono macrumors member


    Oct 9, 2009
    My sata WD 320gb capacity says 319.73 GB (319,728,959,488 bytes).
  4. smmsanders thread starter macrumors newbie

    Aug 27, 2009
    I don't have SATA, I have ATA. I'm using Leapord, too so I probably can't get 320 out of new HD.
  5. Raid macrumors 68020


    Feb 18, 2003
    You may find this article interesting. It's about hard drives and how the size is displayed in base 10 in Snow Leopard (to match the marketing size) instead of the actual (and technically more accurate) base 2 size... that Leopard would display the HD size in.
  6. hodgeheg macrumors regular

    Dec 7, 2008
    Basically, unless you're running snow leopard, which you're not because it's not available for that machine, 320GB means 320 billion bytes, i.e. 320 000 000 000 bytes. Gigabyte is being used in the sense Giga is used in SI units, i.e. as a power of 10.

    Computers generally measure things in powers of 2, so your Mac software measures a gigabyte as 1024 x 1024 x 1024 bytes. This should more accurately be called a Gibibyte, but it is in common use on many computing platforms. This is why Apple have changed their reporting on the newer operating system, to help avoid confusion.

    The bottom line is (until snow leopard), operating systems (Windows, Linux, Mac, any one you like) report capacity in binary gigabytes (i.e. gibibytes) which are larger than SI gigabytes. Hard disk manufacturers report sizes in SI gigabytes, and end up therefore with a larger figure.

    None of your space is missing - your drive is 320GB where GB = 1000000000 bytes. However any operating system available for that computer will measure in GiB (1073741824 bytes), thus you will see a figure somewhere around 290-297.

    You will also 'lose' a small amount of space due to formatting and other information the computer uses to actually know where files are on the disk.

    This will also have been the case on your previous hard drive, and almost any other previous computer, it's just that the difference between the 2 measurements gets larger and more noticeable as capacity goes up. Hence, for example, my 1TB hard disk shows as 931GB on a computer. Your 60GB drive would also have been smaller, but by a much less noticeable amount.

    You still have tonnes of space - be happy!
  7. smmsanders thread starter macrumors newbie

    Aug 27, 2009
    I'm definitely happy and surprised I took apart iBook without any major problems. (knock on wood) I just wondered if I caused the reduction, but now I see that it's based on how storage is calculated.
  8. nickXedge macrumors 6502


    Feb 13, 2008
    Long Island
    And from this we know that you are using Snow Leopard.

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